Yarn tension device for shuttles



March 17, 1942. s". MARCORA 2,275,403

YARN TENSION DEVICE FOR SHUTTLES Filed April 15 1940 2 Shets-Sheefi 1 6Hell March 17, 19 2- e. MARCORA 2,276,408

YARN TENSION DEVICE FOR SHUTTLES Filed April 15, 1940 2 Sheets-Sheet 2H65 50,, I6 55 F" N s Patented Mar. 17, 1942 UNITED STATES PATENT oFHca2,276,408 YARN TENSION DEVICE FOR SHUTTLES Giovanni Marcora, Tradate,Italy Application April 15, 1940, Serial N0. 329,816 In Italy April 2'7,1939 13 Claims. (Cl. 139-218) The invention will be now disclosed withreference to the attached drawing, showing purely an example, limitingin no way the range of the invention, the manner in which the device isapplied to a weaving shuttle.

Fig. 1 is a partial, longitudinal section of a shuttle with theincorporated braking device for the weft;

Fig. 2 is a plan view of the same; v

Figs. 3 and 4 are sections; respectively along lines 3-3 and 4-4 of Fig.2; I

Fig. 5 is a partially sectioned view of a shuttle with an incorporatedalternative convenient embodiment;

Fig. 6 is a perspective view of the strap;

Figs. 7 and 8 are, respectively: a view in front elevation and in plan,with parts removed and cross-sectioned;

Figs. 9 and 10 show the device as applied to the metal part of a shuttlewith self-threading eye, with parts removed or cross-sectioned.

The braking device according to the invention,

' comprises a pair of laminae l0, facing each other: the yarn Funwinding from a spool S or similar (Figs. 1 to 4).

Said laminae are made of a more or less elastic material, hard, as forinstance tempered sprin steel, properly bent.

Each lamina I0 is fixed by means of a glue or other known adhesives to arubber lagging l2, preferably of foamed-rubber. On the opposite side ofthe lamina 10, each pad i2 is covered by a small plate 14 of semi-rigidmaterial, for instance of rubber, leather or the like, so as to obtainan even bearingsfirface and to--favor the adjustment which willbedescrib'ed further on. The pads so composed are retained in thedesired position (see Figs. 1 to 4) by a metal strap l6 operating alsoas a diaphragm for the yarn F and lodged in a cavity of the body of theshuttle N.

Said strap finishes at the bottom with a projeetion l8 in which engagesa pin 20 fi'xed'transversally in the shuttle N so as to prevent theslipping out of said strap.

In order to secure the latter in its position service; the shuttle has,in close proximity of the cavity wherein is lodged the stra a number oftransverse slots 22, in which engage the wines 24 cut out from saidstrap It. This. besides retaining the blocks, protects them from blowsand other stresses which might be brought about by the operation of theshuttle; and particularly prevents any tempering with the device byuntrained workmen, which might reduce the emciency of the device.

The strap has also the function of a diaphragm for the yarn F, and tothis object, is provided at its ends-with holes 26 on a samecentre-line, said holes being united together by a longitudinal slot 28out along said strap and passingthrough the centre of holes 26.

In this way the threading of the shuttle is quick and very practical andmoreover the conditions for self-threading are provided for with thebraking means, should the yarn for any cause get loose.

The braking action brought about by the device specified, is adjustable,by a proper compression of rubber-pad l2. To this object incorrespondence to the middle part of the pad I2, is provided at leastone screw 30 engaged in the shuttles body N, through a rubber sleeve 32applied with glue or other adhesive to the body of the shuttle.

This screw on pressing on the bearing plate ll compresses more or lessthe rubber pad l2, thus varying the braking action.

The sleeve 32 wherein screw 30 screws-in, exerts on the latter a brakingaction, so that said screw cannot get loose under blows or vibrations.

Corresponding to the metal laminae Hi the shuttle N has a hole 34for'discharging the waste fibres forming through the passage of the weftyarn.

The second embodiment illustrated by Figs. 5

and 8, provides for placing the strap I6a within the shuttle N in aposition inclined by 35to 50, slipping it in the slots 22a, cut into theshuttle, by its wings 24a.

A pin 20a engaging an inclined projection l8a of the strap Ilia fixesthe latter to the shuttle.

' The braking surfaces are formed by arched laminae Illa embracingelastically a couple of rubber pads (foamed rubber)- their backs aflexible plate Ila glued to them for the object already stated above.The foamedru bber pads I21: "and the arched laminae Illa are placedwithin the strap I81: and are retained in it by its walls and by bottomwings 36.

In the middle position the walls of the strap 16a have slot 26aaffording a passage for the yarn and on threading-in, the latter entersbetween the braking surfaces passing through a slot 28a connecting thetwo slots 26a. Th inclined position of the strap Ida facilitatesconsiderably the threading of the yarn.

The strap lid is obtained conveniently under the die-press which cuts.it out from sheet metal, bends it and forms the projections which rel2a,having at inforce the part and allow the waste to discharge through holea of the shuttle.

When' the shuttle is self-threading, the inclined position of the padswith braking surfaces is designed as illustrated in Figs. 9 and 10,name- 1y, an inclined eye 31 is out in the body C in which eye areplaced said pads retained by pegs llb fixed in the back part of body C.

The braking action is adjusted, similarly to what has been shown above,by a screw 30b fixed to the body of shuttle N through a rubber sleevefor preventing any loosening of the screw during the operation of theshuttle.

The strength of the shuttle is improved by applying the present device,as it eliminates other cuts in the body of the shuttle which diminishesits strength, thus reducing thenumber of breakages, particularly inshuttles of the so called hygienic pattern."

From the above it is apparent that the weftyarn F threads readilybetween the metal laminae III; a slight pull of the yarn is suflloientto get it wedged in the diverging part of the laminae and introduce itbetween the same.- This happens also automatically when the yarn, due toany accidental cause, leaves the seat of its braki 8.

The device according to the invention, may be applied or incorporated inany pattern of shuttle, or creel, weft winder, and so on after properadaptations according to the case under consideration.

It should be understood that, in practice, the details of design andconstruction as also the scope, may vary without thereby exceeding thelimits of the invention and therefore the patents protection.

What is claimed is:

1. A braking device for yarn in weaving and spinning machines or thelike, especially for weaving shuttles, comprising two foamed-rubber padsfacing each other, with convex active surfaces and curved metal platescovering said pads whereby the yarn can run between the two convexitiesof the aforesaid surfaces and be braked by the reciprocal pressure ofthe said plates, said pressure being regulable.

2. A braking device for shuttles, including a strap, and twofoamed-rubber pads retained in position by said strap and arranged oneagainst the other, with curved contact surfaces and provided with metalplates and means for adjustably pressing one pad against the other.

3. A braking device according to claim 2, characterized by the fact thatthe pads are arranged at an inclination to the longitudinal axis of theshuttle so that the line of contact between the I two curved surfaces isinclined towards the point of the shuttle.

4. A braking device for shuttles, comprising a metallic shuttle eye, twofoamed-rubber pads with curved surfaces covered by metal plates arrangedin a hollow of the said shuttle eye, and a means for regulating thereciprocal pressure of the aforesaid pads.

5. A braking device according to claim 4, characterized by the fact thatthe pads are arranged at an inclination to the longitudinal axis of theshuttle.

6. A braking device as claimed in claim 1, characterized in that saidplates are formed of tempered steel and secured to the adjacent faces ofthe pads by adhesive, and a semi-rigid material covering the oppositefaces of said pads.

7. A braking device as claimed in claim 1, characterized by theprovision of a metallic strap retaining said pads in position andconstituting a diaphragm for the yarn.

8. A braking device as claimed in claim 1, characterized by theprovision of a metallic strap retaining said pads in position andconstituting a diaphragm for the yarn, and projections on said strap,certain of said projections being secured to the shuttle body andanother of said projections being engaged by a pin fastened to theshuttle body.

9. A braking device as claimed in claim 1, characterized by theprovision of a metallic strap retaining said pads in position andconstituting a diaphragm for the yarn, said strap having openings in theopposed walls thereof and aslot connecting said openings.

10. A braking device as claimed in claim 1, characterised by theprovision of means for varying the pressure applied by said pads, saidadjusting means including a rubber sleeve fitted in the body of theshuttle, and a screw adjustably fitted in said sleeve and engaging theadjacent pad.

11. A braking device as claimed in claim 1, characterized by theprovision of a strap retaining said pads in position and disposed at aninclination of from 35 to degrees within the shuttle body, and bottomprojections for retaining the pads.

12. A braking device as claimed in claim 1, characterized by theprovision of a strap for retaining the pads in position and reinforcingprojections providing for ready discharge of the waste.

13. A braking device as claimed in claim 1, characterized by theprovision of a supporting strap for said pads formed by a metallic eyeand an inclined slot.

GIOVANNI MARCORA.

